Synthesis of aliphatic 1,3-diols utilizing reduced ligand concentration and water extraction

A process for producing aliphatic 1,3-diols which comprises:

• a) Contacting at a temperature within the range from about 30 to about 150° C. and a pressure within the range of about 3 to about 25 MPa, an oxirane, carbon monoxide, and hydrogen, in an essentially non-water-miscible solvent in the presence of an effective amount of a homogeneous bimetallic hydroformylation catalyst comprising a cobalt carbonyl compound and a cocatalyst metal which is selected from the group consisting of ruthenium, copper, platinum, and palladium, and which is ligated with a ligand selected from the group consisting of a phosphine ligand, a bidentate or multidentate N-heterocyclic ligand, a porphorine ligand, and a phospholanoalkane ligand, optionally in the presence of a promoter, wherein the molar ratio of ligand to cocatalyst metal atom is in the range of about 0.2:1.0 to about 0.6:1.0, under reaction conditions effective to produce a reaction product mixture containing an aliphatic 1,3-diol;
• b) Adding an aqueous liquid to said reaction product mixture and extracting into said aqueous liquid a major portion of the aliphatic 1,3-diol at a temperature less than about 100° C. to provide an aqueous phase comprising the aliphatic 1,3-diol in greater concentration than the concentration of the aliphatic 1,3-diol in the reaction product mixture and an organic phase comprising at least a portion of the bimetallic hydroformylation catalyst;
• c) Separating the aqueous phase from the organic phase;
• and
• d) Optionally returning at least a portion of the organic phase containing catalyst to step (a).